TITLE:
Extreme Events Assessment Methodology Coupling Debris Flow, Flooding and Tidal Levels in the Coastal Floodplain of the São Paulo North Coast (Brazil)
AUTHORS:
Rafael de Oliveira Sakai, Diego Lourenço Cartacho, Emilia Arasaki, Paolo Alfredini, Alessandro Pezzoli, Wilson Cabral de Sousa Júnior, Maurizio Rosso, Luca Magni
KEYWORDS:
Meteorology; Hydrology; Maritime Hydraulics; Rainfall; Tidal Levels; Extreme Events; Natural Disasters; Geomorphology; Debris-Flow; Flooding
JOURNAL NAME:
International Journal of Geosciences,
Vol.4 No.5B,
October
11,
2013
ABSTRACT:
The North Coastal Region of the State of S?o Paulo,
which comprises the Municipalities of Caraguatatuba, S?o Sebasti?o, Ilhabela
and Ubatuba, is one of the most prone to flooding and debris flow deposition
Brazilian areas, owing to hydrological extreme rainfall events usually coupled
with extreme tidal levels. This risk is also high due to human lives and
material assets, with increasing population rates and the establishment of
large companies such as the Oil industry, with reduced defense/prevention
measures and works.The catastrophic scenario of the city of Caraguatatuba, in March
1967, resulting from one of the most serious natural disasters in Brazil,
fosters discussions about probabilities of heavy rainfall-caused events and
rise in the sea level in coastal areas. Hence, this research is a consequence
of this reality. The research is founded on an innovative methodology based on
the analysis of past data of rainfall and tidal stations, complemented with
debris flow registers in the region of the north coastal zone of the State of
S?o Paulo (Brazil). The anaysis developed involved the meteorological,
hydraulic, geotechnical and statistical knowledge areas.Practical
results are intended to be used for urban planning, designs of macro-drainage,
fluvial, maritime projects and debris flow retention structures. These
practical applications will then associate the probability of occurrence of
certain types of heavy rainfall-caused events such as flooding or debris flow
coupled with a corresponding increase in tidal levels.